The lapping concept is right on.  We use a thick plate of glass and 600
grit wet/dry sandpaper to prep phospher-bronze organ reeds.  Takes out
surface imperfections like nothing else, and it works with all sizes, from
3/4" to 8" reeds.  Of course the reeds are not flat to begin with, and you
need to use "English" while drawing them across the paper to avoid making a
flat spot.

For an oil pump cover, you might want to start with a coarser grit and work
up to 600 or 1,000, and like polishing a telescope lens, rotate the piece
early and often to randomize the wear patterns.

Randy Bergum
1990 Carat
Fullerton, CA

> [Original Message]
> From: George Goff <THX0001@AOL.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Date: 9/13/2005 6:23:43 AM
> Subject: Re: REPLACING OIL PUMP
>
> In a message dated 9/12/05 4:01:44 PM, SDeMocko@FDSMFG.COM writes:
>
> << At warm idle I have just above Zero and at
> 4000 rpm I have about 18 psi.  I was wondering if any one has done a
> write up on replacing the oil pump. >>
>
> Before you pull the pump, you could try lapping the pump cover.  The
cover might have some
> grooves worn into its inner face from the action of the pump impellers.
While
> a lapping plate is nice to use, you do not need anything elaborate for the
> lapping other than a dead flat surface to work against.  A machine tool
table
> with some wet-or-dry abrasive stuck to it will work.  Even a piece of
plate
> glass, the thicker the better, and some valve grinding compound will get
you to
> where you want to be.
>
> George
>